This invention relates to an apparatus for horizontal continuous casting of metal. More particularly, it relates to a device for aligning the starting block in a horizontal continuous casting mold.
Direct chill horizontal continuous casting apparatus typically includes a chilled open-ended mold, including a water box, and a starting block adapted to be inserted into the mold. The starting block is typically moved by a conveyor or roller device into the exit end of the mold to temporarily close the mold for initiation of casting. However, even relatively minor misalignment of the starting block within the mold can result in damage to fragile portions of the mold and water box, especially where the mold opening is of the large size used to produce large ingot for sheet production. Such misalignment can result from lateral shifting of the starting block on the conveyor belt or roller means used for bringing it into position.
Arrangements exist for self-alignment of the bottom block in vertical direct chill continuous casting systems. U.S. Pat. No. 3,847,206 discloses a self-centering bottom block which is slidably mounted on a supporting surface and retaining ring to allow for slight horizontal movement of the bottom block. Guide means on the exterior surfaces of the slidable bottom assembly slide along guide runs which are fixed with respect to the mold bore to center the assembly within the mold bore. The continuous casting apparatus disclosed in U.S. Pat. No. 3,877,508 includes laterally projecting pegs which engage within a tapered ring at the bottom of the mold and a fluid supply under pressure to the underside of the starting block. The block and vertically movable supporting table are arranged so that a fluid forms a thin continuous support film between the periphery of the block and the flat surface of a block support table so that the block may move laterally on the table to be centered automatically when entering the mold prior to casting. Such arrangements, however, are not considered suitable for horizontal continuous casting apparatus because of different structure and orientation considerations. For instance, gravity effects are symmetrical in vertical casting by asymmetrical in horizontal casting.
What is needed, therefore, is a device to facilitate alignment of the starting block in the mold for horizontal direct chill continuous casting apparatus which can be easily used for reducing or eliminating damage of the mold surfaces upon insertion and removal of the starting block. The device should provide a uniform clearance within the mold and be relatively uncomplicated and sure in operation and preferably retrofitable to old equipment.